The present invention relates to a control apparatus for a reflection mirror of a vehicle which automatically effectuates a dazzle-free operation of the reflection mirror such as an interior rear view mirror in accordance with a light incident from the rear of the vehicle.
A dazzle-free reflection mirror employing a liquid crystal panel has been suggested which, by means of a rear light detecting sensor for detecting a light incident from the rear of the vehicle and a front light detecting sensor for detecting a light incident from the front of the vehicle, activates the liquid crystal panel to an opaque condition for effectuating a dazzle-free operation of the reflection mirror when the front and the rear of the vehicle are dark and bright, respectively (for instance, the vehicle runs at night and receives an intensive light from front light bulbs of the following vehicle).
It is disadvantageous however that, when the vehicle enters into a tunnel or a garage where the front of the vehicle is dark and the rear of the vehicle (tunnel entrance or garage entrance) is bright, the reflection mirror is turned into the dazzle-free condition and degrades a rear view image formed on the reflection mirror. That is, as soon as the vehicle enters into the tunnel at which time the eyes of a vehicle driver are not adapted enough to the darkness of the tunnel and the driver does not feel the brightness at the tunnel entrance dazzling, the dazzle-free operation is effectuated and hence the rear view image on the reflection mirror cannot be assured.
Further, undesired repetition of the dazzle-free operation occurs when the intensity of light incident from the rear of the vehicle becomes high and low repeatedly.